Computing devices, communication devices, imaging devices, electronic devices, accessories, or other types of peripheral devices designed to be worn or attached to a user (denoted as wearables or wearable devices) are becoming very popular. Wearables can be considered to be a form of mobile device. Mobile phones with headsets or earbud accessories and the Google© Glass wearable computer are examples of such wearables or mobile devices. Because wearable devices are typically worn by or attached to the user all or most of the time, it is important that wearables serve as a helpful tool aiding the user when needed in all environmental conditions, and not become an annoying distraction when the user is trying to focus on other things.
Handheld devices, wearable devices, and other mobile devices can be exposed to cold ambient temperatures as they are designed to be mobile. Interestingly, many of these devices today still have a minimum operating temperature limit of 5° C., carried over from typical consumer electronics. However in many parts of the world, the minimum ambient temperature outside is much lower than 5° C. Nevertheless, end users have been using, or attempting to use, these devices anyway in cold environments. In most cases, these devices are kept warm inside clothing and people have found that they can use them without any problems for a short time. However, some wearables, such as eyeglass-like wearable devices (e.g., Google© Glass), do not have the luxury of being pre-heated inside clothing, because these devices are worn all the time. As such, active heating of some wearables may be required in cold climates in order to maintain a sufficient working temperature for the devices.